Description

The objective of this technique is to describe the failure that occurs when
an image uses color differences to convey information, but the text alternative for the
image does not convey that information. This can cause problems for people
who are blind or colorblind because they will not be able to perceive the
information conveyed by the color differences.

Examples

A bar chart of sales data is provided as an image. The chart includes
yearly sales figures for four employees in the Sales Department. The
text alternative for the image says, "The following bar chart
displays the yearly sales figures for the Sales Department. Mary
sold 3.1 Million; Fred, 2.6 Million; Bob, 2.2 Million; and Andrew,
3.4 Million. The red bars indicate sales that were below the yearly
quota". This text alternative fails to provide the information which
is conveyed by the color red in the image. The alternative should
indicate which people did not meet the sales quota rather than
relying on color.